Electric arc furnaces for melting metal which utilize a single electrode frequently have to be positioned eccentrically, i.e. off-center in order to avoid overheating of the furnace in a particular quadrant due to arc deflection caused by the field generated by the arc current. The optimal off-center location of the electrode can vary due to the field strength so that a relatively wide opening in the furnace cover is required to permit movement of the electrode to the appropriate position. This situation, with a wide cover opening, is thermally inefficient and with furnace roof covers provided with embedded pressurized water cooling conduits there has been used a center piece with an eccentrically positioned smaller opening. The center piece is also provided with embedded pressurized water cooling conduits and is moveable to position the eccentric opening to the desired position. The foregoing arrangement has the disadvantages of having a pressurized conduit relatively close to the electrode and therefore the electode arc; in the event of arcing to the center piece, high pressure, high volume water leakage results.